How to Work With Concrete Rebar

Concrete Slab Use

• 1

  Measure the length and width of the foundation hole where you’re pouring your slab, using a tape measure. Subtract 10 inches from your measurements to prevent rebar exposure to the air at the edges of the concrete.

• 2

  Cut the rebar to your adjusted length with a hydraulic bolt cutter. Place the bar between the jaws of the cutter and then pump the arms of the cutter to close the jaws together, cutting through the bar where needed.

• 3

  Place a concrete rebar support stone onto the floor of the foundation every 5 feet to raise the rebar to the middle of the slab. Make sure the stones are half the height of the slab to raise the rebar sufficiently.

• 4

  Lay the rebar onto the support stones in two layers, leaving a 5-inch gap at each rebar end between the bar and the form wall. Place the first layer running the length of the slab and then place the second layer over the first, running the width of the slab. Secure the bars in place by tying them together using metal ties that you loop over the bar and then twist together with a pair of pliers. The two layers should create a grid with equal squares throughout, to prevent the concrete from cracking after pouring over the bars.

Concrete Footing Use

• 5

  Measure the length of the footings to determine rebar length. Subtract 10 inches from the length to avoid exposure of the rebar to air, and then cut the rebar with the hydraulic rebar cutter.

• 6

  Place two rows of rebar into the footing with support blocks, raising the bars to the center of the footing form height. Space the rebar evenly in the footing, with an equal amount of space between the bars and the form sides.

• 7

  Tie the bars to the blocks with metal ties to hold them steady while pouring the concrete into the footing.

• 8

  Use bent rebar supplied by the manufacturer in corners of the form, tying the bars in place as you did the straight rebar.

Vertical Rebar Placement for Blocks

• 9

  Drill a 1/2-inch hole into the foundation using a jack hammer drill, penetrating to a depth of 12 inches for each horizontal bar of rebar. Space the holes 4 inches from the edge of the slab, with 16 inches between the centers of each hole.

• 10

  Place separate rows of holes for each reinforced load-bearing wall you intend to build into the structure.

• 11

  Cut a piece of rebar to a length of 3 feet using the hydraulic rebar cutter for each hole drilled into the foundation.

• 12

  Drive the rebar into the drilled holes using a small sledge until each bar extends to a height of 24 inches from the slab.